Anatomy & Physiology Study Guide

Sensory receptors

Specialized cells detecting stimuli like touch, pressure, temperature, and pain

Brachial plexus

Network of nerves supplying the upper limb with 5 terminal nerves

Medulla

Most inferior, has vital & non-vital centers/reflexes

Pons

Superior to medulla, connects different parts of the brain together, pneumotaxic center for breathing

Mid Brain

Superior to pons, red nucleus & substantia nigra for muscle control

Diencephalon

Between cerebrum & midbrain, contains thalamus, hypothalamus, & epithalamus

Cerebellum

"Little brain", skilled muscle movements, posture & balance

Cerebrum

Largest part of the brain, outer is gray matter & inner is white matter, contains limbic system

Golgi tendon organ

Sensory receptor in tendons detecting muscle tension to prevent over-contraction

Muscle Spindles

Sensory receptors sensitive to change in length of the muscle and the rate of that change.

Hypothalamus

Control of ANS, hormone production, regulate emotional & behavior patterns, regulation of eating/drinking, control of body temp, regulation of circadian rhythms

Mechanoreceptors

respond to touch, pressure, vibration, stretch, and itch

Chemoreceptors

respond to chemicals (smell & taste)

Thermoreceptors

respond to changes in temperature, mostly in skin

Nociceptors

pain receptors

Photoreceptors

Vision

Free Nerve Endings

Most abundant type of sensory receptor, they are nociceptors (pain)

ANS- ACh

All postganglionic neurons release ACh

ANS- Norepinephrine

Only in sympathetic, excitatory in cardiac muscle, inhibitory in blood vessel

Nicotinic Receptors

ACh has excitatory effect on muscles

Muscarinic Receptors

ACh relaxes bladder

Membrane potential

Voltage difference across a cell membrane due to different ion concentrations

Action Potential (nerve impulse)

sequence of events in the axon which quickly reverses the membrane potential and then returns it to the resting state

Steps of an Action Potential

1. Membrane starts at RMP (-70mV) Polarized phase

2. Stimulus is applied

3. Membrane reaches threshold potential (-55mV)

4. Triggers gated Na+ channels to open

5. Na+ diffuses into the cell, Depolarizing phase

6. Na+ channels close, K+ channels open, & sodium-potassium pump is activated

7. K+ diffuses out of the cell, Na+ is pumped out of the cell, Repolarizing phase

8. RMP is restored

Reflex Arc Components

Sensory receptor, sensory neuron, interneuron, motor neuron, effector

Types of muscle contractions

Isotonic (concentric and eccentric) and isometric muscle actions

Hyaline Cartilage

Most common, found in synovial joints

Fibrous Cartilage

Found in intervertebral disks & pubic symphysis

Muscle Fiber Anatomy

Endoneurium (small, individual fiber), Perineurium (medium, fiber bundle), Epineurium (big, complete muscle, fascicles & blood vessels)

Accommodation actions

Adjustments in the lens shape for near and far vision clarity

CVA- Stroke

Hemorrhage or cessation of blood flow through cerebral blood vessels

Cerebral Palsy

Damage to motor areas of brain tissue during birth

Dementia

Degenerative disease that causes destruction of neurons

Alzheimer's Disease

Form of dementia, lesions develop in the cortex in middle to late adulthood

Huntington's Disease

Inherited, characterized by involuntary movement

Poliomyelitis

Destroys anterior horn motor neurons, produces flaccid paralysis